On 5/9/11 5:40 PM, Mag Gam wrote: > Are stride settings needed for Hardware RAID devices? > > For example, if I do a RAID 5 on a HP-P800 I get a 9.1TB filesystem. > Should I worry about stride in that case? stride is useful so that you don't end up with metadata hotspots on a single disk. this is true whether the disks are raided together in hardware or in software, I think. -Eric > > On Wed, Mar 16, 2011 at 2:02 PM, David Shaw <dshaw@xxxxxxxxxxxxxxx> wrote: >> On Mar 15, 2011, at 6:53 PM, Eric Sandeen wrote: >> >>> On 3/15/11 5:42 PM, David Shaw wrote: >>>> Hello, >>>> >>>> I understand the need for a proper stride setting when formatting a >>>> filesystem on a RAID device. However, is there any problem in using >>>> a stride setting when formatting a filesystem on a regular non-RAID, >>>> non-SSD, just plain-vanilla-single-disk block device? I'm sure there >>>> isn't any benefit to it, but I'm curious if there is any harm. >>>> >>>> The reason I ask is I'm looking at some code here that can be used on >>>> either RAID or non-RAID devices. The stride setting it has is >>>> correct for the particular RAID setup it is intended for, but it also >>>> uses those settings when formatting a non-RAID device. >>>> >>>> David >>> >>> just FWIW, recent kernels & e2fsprogs will just automatically pick >>> stride based on storage geometry - for md/lvm at least, and for >>> scsi devices that export this geometry as well. >>> >>> ext4 has a little stripe-awareness in its allocator; otherwise, stride >>> just staggers bitmap starts so they don't all end up on the same spindle; [1] >>> Offhand I don't think it'd cause any harm to set stride on non-raid. >> >> Thanks very much for your pointers. It's a nice enhancement that this is done automatically now. >> >> David >> >> >> _______________________________________________ >> Ext3-users mailing list >> Ext3-users@xxxxxxxxxx >> https://www.redhat.com/mailman/listinfo/ext3-users >> _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
